What do external nares do

External nares, or nostrils, perform the basic function of being the passageway through which oxygen enters the body. Nostrils have many different parts within them that perform their own individual functions.

Nostrils of mammals and birds have cartilages called turbinates. These turbinates warm the oxygen brought in through the nostrils to help the lungs function more efficiently and humidify the air to prevent dryness of the lungs.

In between the nostrils is the septum. It consists of four bones and cartilage and serves the functions of separating the right and left nasal cavities, providing support to the nose and regulating airflow into the nasal passages.

At the top of the septum, humans have two additional, internal nares. The two internal or posterior nares choanae are the openings leading from the nasal cavity into the pharynx. From: nares in Concise Medical Dictionary ».

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Oxford Reference. Publications Pages Publications Pages. Looking for extra anatomy learning tools? Check out this ultimate guide to studying anatomy. The vestibule is the portion of the nasal cavity that lies directly posterior to the external nares. It is lined by stratified squamous epithelium providing as a barrier that helps protect the vestibule from damage.

A layer of mucus typically covers the outer surface of the vibrissae. There are three turbinates on each side of the nasal cavity Superior, middle, and inferior. Grooves are found between the curved turbinates.

During inhalation, air is directed over and under the turbinates.